Concrete mixer



Jan. 20, 1942- J. H. FITZGERALD CONCRETE MIXER Filed April 2, 1941 3Sheets-Sheet l g N N a m\ E a R E Q I\ mm mm *m w we 3 I m g mm s mm m aum mm 3 Q A4 a w n 2 2 a E i \m w a i Q Jan. 20, 1942. J. H. FITZGERALDCONCRETE MIXER 3 Sheets$heet 2 Filed April 2, 1941mlllllllllllllllllllllllllHI|Hlllllllllllllllllllllllll fl'fzgerald Jan.20, 1942- J. H. FITZGERALD CONCRETE MIXER Filed April 2, 1941 3Sheets-Sheet 3 ually shifted from an open to a closed position.

Patented Jan. 20, 1942 vireo starts" OFFICE CONCRETE MHXER James H.Fitzgerald, Westfield, N. J.

Application April 2, 1941, Serial No. 386,543

9 Claims. (01.

Also in such types of concrete mixers the, discharge door is manuallyoperated and necessi-zy tates the operator of the mixer to mount thetruck frame or chassis to gain access to the usual hand wheel for theoperation of the discharge door.

In the type of concrete mixer in use at the pres-:- o ent time therevolving drum is charged with the dry aggregate and a water tankcarried by the truck is usually provided with two comp-artments, onecompartment containing the greater quantity of water for controlleddelivery to the; aggregate in the drum for mixing therewith, while theother smaller compartment contains rinse water controllably fed to thedrum for cleaning the latter after discharge of the mixed his garments.

It is therefore the primary object of the pres-, 40 ent invention toimprove the construction and operation of both the charging anddischarging 1 doors for the drum of the concrete mixer and to I improvethe water charging facilities for the two compartments of the water tankthat deliverswater to the drum.

A further and important object of the invention is to provide pneumatic,hydraulic or vacuum devices for the operation of the charging anddischarging doors for the mixer drum with,

said doors operable from remote points, thereby eliminating thenecessity of an operator climbing over the frame of the truck carryingthe drum to gain access to the doors.

A further and important object of the invender of the ram.

tion is to improve the water charging facilities for the twocompartments of the Water tank whereby a single filling opening isprovided with branch means for delivering water simultaneously to themixing and rinse Water compartments of the tank together withatelltaledevice or indicator to show when the two compartments of the water tankhave been charged with the proper amount of water so that a signal maybe given by the operator filling the tank to shut off the water supply.I

With the above and other objects in view, the

' invention consists in general of certain novel details of constructionand combination of parts hereinafter more fully described, illustratedin the accompanying drawings and specifically claimed.

In the accompanying drawings:

Fig. 1 is a vertical longitudinal sectional view of a concrete mixerconstructed in accordance with the present invention, a part of theframe structure of the carrying truck for the concrete mixer drum beingfragmentarily illustrated, showing the ram operated charging anddischarging doors and the improved water tank filling means.

Fig. 2 is a fragmentary top 'plan View, partly broken away and shown insection, to illustrate the clevis bars carried by the ram for theoperation of the discharge door.

Fig. 3 is an enlarged fragmentary vertical longitudinal sectional viewshowing the conduit means for the pneumatic, hydraulic or vacuum powerdevices extending through the mixer drum for communication with theram-operated charging door,

Fig. 4 is an enlarged fragmentary longitudinal sectional view showingthe ram-operated charging door in its closed position and the motivesupply means communicating with the cylin- Fig. 5 is a cross sectionalView taken on line 5-5 of Fig. 4, showing the'elevated plate carryingthe ram providing, a chamber for the reception of the charging door whenin open poparts of the motor truck are illustrated as providingsupporting elements for certain parts of the present invention, thetruck parts illustrated include base rails 10 from the rear ends ofwhichrise perpendicular channel irons II. The mixer drum comprises acylindrical wall I2 having front and rear tapering end wall portions I3and I4, respectively, the tapering end wall portion I4 being offrusto-conical form and providing a discharge opening I5 adapted to beclosed by the door designated in general by the reference character I6.The cylindrical wall l2 of the drum has a charging door opening IIadapted to be closed by the charging door designated in general by thereference character l8. In mixer drums of this general character thereis usually provided at the forward end thereof, such as in continuationof the forward tapering end wall portion I3, a straight end wall I9extending beyond the forward portion of the tapering end wall I3 andfashioned as a gear wheel 20 adapted for engagement with the usual drivepinion of the truck mechanism.

As shown in Fig. 1 a part of the frame structure 2| encloses the endwall I9 and gear 20 of the mixer drum and within said frame structure 2|there is provided a standard or base support'22 having a shaft bearing23 at its upper end for the support of a shaft that extends through thedrum and upon which the latter is rotatably mounted.

A hollow shaft 24 extends axially of the mixer drum I2, the forward end24" of the shaft being annularly enlarged and having a support in thebearing 25 carried axially of the forward end wall IQ of the drum, therear end 24 of the tubular shaft 24 terminating adjacent the rear end ofthe cylindrical wall l2 of the mixer drum. A pair of water bells 25 and21 are carried by and are in communication with the tubular shaft 24,the water bell 21 being secured to the rear terminal end 24 of the shaft24, the water bell 26 being mounted on the shaft between the endsthereof. The support for the rear end of the shaft 24 within the drum I2comprises a tubular shaft having end leg portions 28 and 29 connected attheir outer ends to the cylindrical wall I2 of the mixer drum, the innerends of the leg portions 28 and 29 terminating in proximity ofthelongitudinal axis of the mixer drum and carrying a forwardly directedfitting 30 secured to the outer bell 21 and a rearwardly directed nipplefitting 3| for purposes presently to appear.

The mounting for the discharge door I6 comprises a shaft 32 arrangedcoaxially with the tubular shaft 24, the forward end of the shaft 32being rigidly secured to the nipple fitting 3| as shown in Fig. 3 andbeing of a length to extend outwardly through the discharge door openingI5, said shaft 32 having an axial bore 33 extending therethrough, withthe bore communicating with the legs 28 and 29 of the transverselyextending tubular shaft that supports the rear end of the shaft 24. Abearing collar 34 rotatable with and slidable upon the shaft 32 carriesa peripheral flange 35 to which the central portion of the web 36 of thedischarge door I6 is connected, the discharge door I6 comprising saidweb 35 that carries at its peripheral edge a V-shaped flange includingflange walls 31 and 33, the flange wall 31 being located for engagementwith the outer face of the tapering rear wall portion I4 of the mixerdrum outwardly of the discharge door opening l5 to form a closure forsaid opening. To facilitate sliding movement of the bearing collar 34upon the shaft .32, an elongated sleeve 39 surrounding the shaft 32 hasone .end secured as at .40 to the forward end of the bearing collar 34,while the other end of said sleeve is provided with a cap .4! inproximity of the nipple fitting 3| and so disposed when the dischargedoor I6 is in its closed position.

The discharge door I6 with its bearing collar 34 is slidablelongitudinally of the shaft 32 when moving from open to closed positionsrelative to the discharge opening I5 in the mixer drum and saiddischarge door may be pneumatically or hydraulically operated, oroperated in the presence of vacuum, and as illustrated and for purposesof clarity only, the operating means for the discharge door will bereferred to as pneumatically operating means. As shown in Figures 1 to3, an angular and transversely extending channel iron 42 is connected atits ends to the upright channel iron II and occupies a position slightlybelow the alined shafts 24 and 32, the channel iron 42 being positionedrearwardly of the discharge door and its opening and carryingintermediate the ends thereof a platform 43 for the support of a ram. Apair of angle brackets comprising upright legs 44 with base flanges 45are respectively secured in spaced relation to the front and rear edgesof the platform 43, the vertical legs 44 .of the brackets providing asup.- port for the cylinder 46 of the ram. The cylinder 4.6 ,of the ramhouses a reciprocating piston 41 that carries a piston rod 48 extendingthrough the :forward end of the cylinder 46, the forward end of thepiston rod 48 having a forked pivotal connection 49 with a pair ofdivergent clevis arms 50. As shown more clearly in Fig. 3, that portionof the bearing collar 34 projecting rearwardly of the web 36 of thedischarge door I6 is provided with an annular groove 5| in which grooveis freely mounted a collar or ring 52 carrying diametrically oppositeradially projecting pins 53 received in pivot openings formed in theforward ends of the clevis arms 50.

The supply of air to the cylinder 46 of the ram for the operation of thepiston 41 includes a pipe line 54 extending from a controlled source ofenergy, the pipe line 54 as illustrated in Figs. 1 to 3 being incommunication with a transverse- 1y extending pipe line having legportions 55 and 56, the leg portion 56 of the pipe line being incommunication with the outer end of the ram cylinder 46, while the leg'55 of the pipe line is in communication with the side of the cylinder:46 adjacent its forward end as illustrated.

It will be understood that the mixer drum I2 is rotatably supported upona carrying truck and that the shafts 24 and 32, the tubular shaftsupport comprising legs '28 and 29 and the discharge door I6, rotate asa unit while the ram device and its associated clevis remain stationaryby reason of the ring connection 52 with the collar 34 carried by thedischarge door.

The charging door opening I I and its associated charging door I8 areset into the depressed wall portion 12 of the cylindrical drum I2 and aram'for the operation of the charging door I8 is alsoxsupported on saiddepressed wallportion. The charging door and the operating meanstherefor comprise a charging door 5;! supported at its side edges andslidable upon a pair of rails 58 carried by the wall portion I2 atopposite sides of the opening la], the guide rails '58 extending aconsiderable distance rearwardly of said charging opening I! for thesupport .of the door 51 when in its open position. Alsoa pair of crossrails 5.9 extend transversely of the charging opening I! at the frontandrear edges theredoor 51 comprises a ram similar in construction andoperation to the ram for the operation of the discharging door, the ramfor operating the charging door 51 comprising a cylinder 60 supported atits ends in the vertical legs 6| and 62 of angle brackets, the baseflanges 63 of the angle brackets being mounted upon and secured to thefront and rear ends respectively of a raised plate 64 having dependingside flanges 65- anchored to the depressed wall portion I2 of the mixerdrum as clearly shown in Figs. 4 and 5, this arrangement of the raisedplate 64 providing a chamber 66 for the reception of the charging door51 when in its retracted open position. From an inspection of Fig. 6 itwill be noted that a pair of longitudinally extending guide flanges 61are carried by the wall portion I2 at opposite sides of the door openingI! that overlie opposite side edges of the charging door 51 for holdingthe same tightly engaged with the track rails 58 when the charging dooris in its closed position.

The cylinder 58 of the ram for operating the charging d-oor houses areciprocating piston 68 and said piston carries a forwardly extendingpiston rod 69 that has a pivotal connection 10 at its forward end with apair of upstanding lugs 7| that are secured at their lower ends as at 12to the forward end of the charging door 51. It will be understood froman inspection of Fig. 4 that when the piston 68 moves rearwardly in thecylinder 60 of the ram, the door 51 will be retracted into its openposition relative to the charging opening I! and be received in thechamber 66 afforded by the raised plate 64.

It is also understood that the ram for the operation of the chargingdoor |8 may be pneumatically or hydraulically operated or operated inthe presence of a vacuum and pneumatic means for the operation of theram only will be described. As shown in Fig. 3 the rearwardly projectingend of the pipe 32 that supports the discharge door I6 has an axial bore33 therein covered by an end cap 13 with a gasket 14 interposed betweenthe end of the shaft 32 and said cap 13, there being axial openings inthe cap and gasket for the passage of a stationary nipple 15 that isadapted to be placed in communication with a source of motive fluid. Thestationary nipple l terminates slightly beyond the gasket 14 and is incommunication with a relatively small fluid pipe line 16 extendingthrough the bore 33 of the shaft 32 and being rotatable with said shaft.The forward end of the pipe line 16 is bent at right angles and extendsthrough the supporting leg 28 of the strut for the support of the rearend of the tubular shaft 24, said pipe line 16 passing outwardly of themixer drum through the depressed wall portion l2 as shown in Figs. 4 and5 for communication with a transversely extending pipe line having pipeline leg portions 1'! and 18, the leg portion 11 communicating with thecylinder 60 of the ram through the side wall thereof adjacent theforward end, while the leg portion 18 communicates with the rear end ofthe cylinder 60. The placement of the pipe line 16 in the axial bore ofthe shaft 32 and in the tubular supporting leg 28 for the shaft 24protects the pipe line from the excessive weight and impact of theaggregate material within the mixer drum.

The water tank for the concrete mixer is illustrated in Fig. 1 and is incommunication with the tubular shaft 24 for supplying mixing water tothe water bells 26 and 21 within the mixer drum. The water tank 19 issupported on the frame structure 2| forwardly of the mixer drum and atan elevation above the tubularpipe 24 for the gravitational flow ofwater to said pipe, but it is to be understood that a pump may beinterposed in the water supply line if desired. A partition is arrangedin the tank 19 to provide a relatively large compartment 8| for mixwater to be delivered to the drum l2 and a relatively small compartment82 for rinse water for delivery to the mixer drum for cleaning thelatter. It has heretofore been the practice to provide separate watercharging openings for the mixing and rinse water compartments of a watertank,

but to overcome the serious objections to'suchpractice, thepresentinvention provides a single water charging opening for the tankwith means for directingthe water into both compartments. A single waterfilling neck 83 rises from the tank 19 above the mixing watercompartment 8| to be closed by a cap 84, the lower end of the waterfilling neck 83 within the mixing water compartment 8| having branchoutlets 85 and 86,,the outlet 85 discharging into the mixing watercompartment 8| ,while outlet 86 extends through the partition 88 and isprovided at its discharge end with a gravitationally closing valve 81,Water delivered to the tank 19 through the sin. gle neck opening 83flows into both compartments 8| and 82, the latter compartment whenfilled having the supply thereto cut off by the gravitationally closingvalve 81 and when the mixing water compartment 8| has been filled to thedesired level, the telltale device or float indicator 88 will rise abovethe tank 19 so that the supply of Water to the tank may be out off. Forthe controlled delivery of the water from the compartments 8| and 82 ofthe tank 19 tothe tubular shaft 24 and water bells 26 and 21, there isprovided a pipe connection 89 between the compartment 8| of the tank andthe T-fitting 90 with a control valve 9| in the pipe connection 89,while a pipe connection 92 with a control valve 93 therein is incommunicationwith the other end of the T-fitting 90. A flexible tubularconnection 94 is formed between the T-fitting 96 and the tubular shaft24.

As hereinbefore stated, it has been necessary with the present type ofconcrete mixers, for operators thereof to climb over the machine foraccess to and operation of the charging and discharging doors of themixer drum, but with the present invention the operator may remotelycontrol the discharging and charging door either pneumatically,hydraulically, or in the presence of vacuum. It is the usual practice torotate the .drum |-2 during the delivery of the concrete we duringnormal operation rotates in a clockwise direction and the internal vanes85 upon theinner wall of the drum in addition to agitating the aggregatetend to move the same away from the discharge door opening I5. When thematerial is to be discharged and the discharging door l6 opened'by theram, the drum is rotated in a counter-clockwise direction and theinternal vanes or ribs 95 effect the discharge of the mixed concrete tothe discharging opening l5.

From the above detail description of the invention, it is believed thatthe construction and operation thereof will at once be apparent, and

while there is herein. shown and described the preferredembodimentthereof, it is to be understood that minor changes may be made in thedetails of construction, such. as will fall within the scope of theinvention as claimed.

Iclaim: f

1. In a truck mixer for concrete and the like a rotatable mixer drum,said drumhavingjfilling and discharging openings therein, a slidablymounted closure door for each openin a ram for operating each door and aplatemounted in spaced relation to the wall of the drum for the supportof the ram for operating the filling open.- ing closuredoor andlaterally of said filling opening, said ram having a piston rod attachedatiits forward end to theforward end of the filling opening closure doorwith the latter when in open position slidable into the space betweenthe wall of the .drum and the plate supporting'the ram. a

2. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having filling and. discharging openings therein, a slidablymounted closure door for each opening, a ram for operating each door, aplate mounted in spaced relation to the wall of the drum for the supportof the'ram for operating the filling opening closure door and laterallyof-said filling opening, said ram having a piston rod attached at itsforward end to the forward end of the filling opening closure door withthe latter when in open position slidable intothe space between the wallof the drum and the plate supporting the ram and the wall of the drumsupporting the filling opening closure door and operating ram thereforbeing countersunk to substantially maintain the overall radialdimensions of the drum.

3. In a truck mixer for concrete and the like, a rota-table mixer drum,said drum having filling and discharging openings therein, a closuredoor for the discharge opening, a slidably mounted closure door for thefilling opening, a ram for operating the filling opening closure door, ahollow shaft in said drum for the support of water bells, said shaftbeing supported at its forward end in the front end of the drum, atubular strut extending transversely of the drum and providing a supportfor the rear end of the hollow shaft and an operating fluid supplyconduit for the ram extending through said tubular strut.

' 4. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having filling and discharging openings therein, a closuredoor for the discharge opening, a slidably mounted closure door for thefilling opening, a rainfor operating the filling opening closure door, ahollow shaft in said drum for the support of Water bells, said shaftbeing supported at its forward end in the front end ofthe drum, atubular strut extending transversely of the drum and providing a supportfor the rear end of the hollow shaft, an operating fluid supply conduitfor the ram extending through said tubular strut, an

axial shaft at the rear end of the drum upon which the discharge door ismounted and being supported at its forward end on the tubular strut andsaidfluid supply conduit extending through said axial shaft andexteriorly of the drum for communication with a source of energy.

5 In a-truck mixer for concrete and the like, a rotatable mixer drum,said drum having filling and discharge openings therein, a slidablymounted closure door for each opening, an axial shaft in the drumprojecting through the discharge opening for the slidable support of thedischarge door, a'ram for operating each door and the shaft for thesupport of the discharge closure door forming a part of a conduit forthe supply of operating fluid to the ram for operating the fillingopening closure door.

6. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having a discharge opening therein, a slidably mounted closuredoor for said opening, an axial shaft in the drum projecting throughsaid opening for the slidable support of the door, a ram supportingframe rearwardly of thedrum, and a ram on the supporting framecperatively attached to said door.

'7. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having a discharge opening therein, a slidably mounted closuredoor for said opening, an axial shaft in the drum projecting throughsaid opening for the slidable support of the door, a ram supportingframe rearwardly of the drum, and a ram on the supporting frame axiallyalined with said shaft and operatively attached to said door.

8. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having filling and discharge openings therein, a slidablymounted closure door for each opening, an axial shaft in the drumprojecting through the discharge opening for the slidable support of thedischarge door, a ram for operating each door and the shaft for thesupport of the discharge closure door forming a part of a conduit forthe supply of operating fluid to the ram for operating the fillingopening closure door and a frame structure rearwardly of the mixer drumfor the support of the closure door operating ram with the ram axiallyalined with said shaft.

9. In a truck mixer for concrete and the like, a rotatable mixer drum,said drum having filling and discharge openings therein, a slidablymounted closuredoor for each opening, an axial shaft in the drumProjecting through the discharge opening for the slidable support of thedischarge door, a ram for operating each door and the shaft for thesupport of the discharge closure door forming a part of a conduit forthe supply of operating fluid to the ram for operating the fillingopening closure door, and said drum having a countersunk portion in theside wall thereof for the mounting of the ram and closure door for thefilling opening.

' JAMES H. FITZGERALD.

